Lipids are essential in maintaining cell structures, and are believed to play important roles in energy storage and cellular signalling. It is further believed that lipids are important in the pathophysiology of diseases, such as, cancer, neurodegenerative diseases, infections, diabetes etc. Thus, there is an understanding that studies on the lipids could further our understanding of mechanisms of diseases, including the identification of biomarkers and potential drug targets. However, due to their chemical and structural complexity, low concentrations, and complicated properties, there is a major analytical challenge to separate and characterize lipids of various classes from a biological sample.
Among the lipids, plasmalogens, a class of phospholipids, are widespread in human tissues, consisting of approximately 18% of all the phospholipids in a human body (Hermetter A., Comments Mol. Cell Biophys. 1988; 5:133-149). Plasmalogens are structural membrane components and a reservoir for secondary messengers. It is believed that plasmalogens are involved in membrane fusion, ion transport, and cholesterol efflux. Further, plasmalogens are believed to be a cell internal antioxidant, scavenging reactive oxygen species (Brosche T et al., Exp. Gerontol. 1998; 33:363-9). Despite of the importance recognized with plasmalogens, there has been very limited progress in understanding the exact role and action of plasmalogens due to their poor separation and characterization from other lipids.
Clearly, there is a need for the development of a simple and effective analytical method for separating lipids of different classes (especially, plasmalogens) from biological samples.